Trays or other containers with absorbent litter therein are commonly used by cats or other pets for excretion of wastes. The wastes must frequently be removed from the litter, or the litter must be changed, to prevent odors and for hygienic reasons. Even if wastes are frequently removed from the litter, at some point the litter must be completely replaced because there is no method known in the art to completely remove all waste from the litter.
Various devices that provide a litter box or pet relief station are known in the art. For example, U.S. Pat. No. 4,011,837 issued to Ksioszk, discloses a self-cleaning animal kennel in which an impervious sheet is moved along the floor of the kennel. Absorbent paper and a deodorant is automatically applied over the impervious sheet and collected animal waste, as the sheet passes from the kennel floor with the two superimposed sheets and captured waste being rolled up on a drum.
U.S. Pat. No. 4,465,018, issued to Mopper, discloses an indoor pet relief station in which a plastic sheet is dispensed from a roller and is moved across the floor of the device by a motor driven take-up roll. Fresh litter, dispensed from a hopper, is deposited on the surface of the moving plastic sheet. As the plastic sheet passes onto the take-up roll, soiled litter falls downwardly into a disposable collection bag. A screen positioned immediately above the collection bag allows the used litter to pass into the collection bag, but prevents passage of solid waste. According to the Mopper patent, the filtered litter can be reused, while the separated solid waste is disposed of. However, it is readily apparent to those skilled in the art, that merely filtering litter neither removes all waste from the litter, nor prevents the buildup of odor and unsanitary conditions.
A pet relief station disclosed in U.S. Pat. No. 4,493,288, which issued to van der Kolk, includes a hopper for supplying litter to the upper end of a conveyor belt. When an animal enters the litter box, the conveyor belt operates to move used litter from the lower end of the conveyor belt into a container. Simultaneously, fresh litter is deposited by the hopper.
In a pet relief station disclosed in U.S. Pat. No. 4,787,334, which issued to Bassine, litter is deposited by a supply hopper onto a movable plastic sheet. When a crank is turned, the sheet is wound on a roller, sealing the used litter in the rolled up plastic sheet.
Although prior art devices of the above-described type may be satisfactory in some situations, various disadvantages and drawbacks exist. For example, none of the described devices provide for the cleansing or otherwise recycling of used litter, or its automatic resupply to a storage hopper.